The present invention relates to multiplexer circuits for effecting in successive phases of operation actuation of selected capacitance actuated devices arranged in respective groups.
One application of such a multiplexer circuit is a pulsed droplet deposition apparatus, such as a drop-on-demand ink jet printer having an array of channels from which ink droplets are ejected. In such a device, the ink channels may be arranged in groups, channels from the respective groups being selected for printing droplets in successive phases of operation of the multiplexer circuit. In so-called drop-on-demand printers, the actuating circuits are required to handle substantial currents which give rise to the risk of burn-out failure. Further, in known forms of pulsed droplet ink jet printers, switching of the large actuating currents typically gives rise to excessive radio frequency interference.